The present invention relates to a surface barrier to protect an asset such as a ship that abuts a body of water.
There are numerous situations in which a waterfront asset, such as military and civilian ships, that are situated in a harbor environment must be protected. Potential threats to the waterfront asset may originate at the surface of the water or below the surface of the water that abuts the asset. Typically, protective systems are passive barriers, such as oil booms or heavy fixed barriers to stop boats, or simple lines of small floats on the water. Security boom systems are typically heavy, usually difficult to deploy and moor, and are not intended to be portable. Moreover, security booms usually cannot be seen at night or in fog or rain, and do not provide any indications of intrusion.
Consequently, a method and apparatus that may provide continuous protection for an asset by automatically warning personnel about a possible intruder, that has a reduced cost, that has mobility so that the protective system may be transported with the ship as the ship changes locations, that can be configured for a desired perimeter typology, and that uses less power while providing a required degree of protection from surface and underwater predators would be beneficial to advancing the art of protective systems for waterfront assets.
A harbor fence system may be deployed in water around ships or other waterfront assets to serve as a line-of-demarcation (visible day or night or in fog) to warn boats to stay out of the enclosed xe2x80x9csecurity zonexe2x80x9d or exclusion zonexe2x80x9d and to provide warnings and the location of any attempted intrusion across the harbor fence system. The harbor fence system may be lightweight and portable, capable of being transported on different sizes of ships (such as a navy ship), and deployed in different harbors where a ship may dock throughout the world in order to establish a security perimeter. The harbor fence may also be used to protect commercial ships, e.g. tankers and cruise lines) or other waterfront assets (e.g. buildings and bridges) abutting harbors, lakes, or rivers.
In one embodiment of the invention, a harbor fence system comprises a series of spars that protrude above the water surface, that are spaced approximately uniformly, and that are connected to an electrical computer with a telemetry subsystem. Each spar contains electronic sensors, e.g. water immersion sensors and accelerometers, and circuitry to detect intrusions and to communicate the location of the intrusion to a computer control station on shore or on the watch deck of the associated ship. The embodiment also facilitates deploying and retrieving the harbor fence system.
Additionally, the embodiment may also determine whether an underwater intruder is passing under a protective boundary, in which the harbor fence system interfaces to an underwater sonar sensor subsystem.